1. Field of the Invention
This invention relates to a process for preparing bisphenols. More particularly it relates to a process for preparing bisphenols wherein a sulfonic acid type cation exchange resin partially modified with a pyridinealkanethiol is used as a condensation catalyst.
2. Description of the Prior Art
It is well known to use a sulfonic acid type cation exchange resin partially modified with an aminothiol as a catalyst in the condensation of a phenol with a ketone to prepare a bisphenol. For example, Japanese Patent Publication No. 19953/1971 discloses the use of an aminoalkanethiol having 1 to 4 carbon atoms such as 2-aminoethanethiol as an aminothiol modifier useful for the above process and Japanese Patent Laying-Open Publication No. 19189/1977 discloses the use of 4-aminothiophenol for the same reaction. However, as these catalysts still suffer from lower reaction rates and selectivities, a catalyst capable of producing bisphenols at higher reaction rates and with higher selectivities has been sought after.